Rotary engine



( No Model.) 2 Sheets-Sheet 1.

- G. T. ELLIS.

B -wr g Patentedlan. 25,1881.

".FE EHS. FMOTO-UTNOGRAPHER. WASHINGTON. 0,6 7

UNITED STATES PATENT OFFICE.

A GEORGE T. ELLIS, OF OSWAYO, ASSIGNOR OF ONE-FOURTH TO CARLTON J.

' CURTIS, OF BRADFORD, PENNSYLVANIA.

RorARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 237,002, dated January 25, 1881.

Application filed June25, 1880. (N0 model.)

To all whom it may concern: 1

Be it known that I, GEORGE T. ELLIs, of Oswayo, in the county of Potter and State of Pennsylvania, have invented a certain new and Improved Rotary Engine; and- I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings,forming part of this specification, in which- Figure 1 is a side elevation of an engine constructed in accordance with my invention; Fig.2, a front elevation of the same; Fig.3, a sectional view'taken' onthe line as as, Fig. 1; Fig. 4, a similar view taken on the line .00 00 Fig. 2 Fig. 5, a similar view taken on the line 00 .90 Fig. 1; Fig. 6, a perspective view of one of the piston-valves; and Fig. 7, a detail view, showing one of the piston-valves and the surface against which it bears when projected.

Similar letters of reference in the several figures denote the same parts.

This invention-relates to improvements in rotary engines, audit consists ina novel construction and arrangement of parts, as I will now proceed to describe.

In the drawings, A represents the stationary casing of the engine, having an internal annular projection or fixed ring, A, and stout lugs or flanges A by which to attach it to a supporting-frame, A by bolts or otherwise.

B is acylindrical piston, mounted on a shaft, B,within the fixed ring A, and projecting on each side of thering, and provided with fixed heads B which bear against and are adapted to slide'in contact with the side faces of the ring. The stationary casing is also provided with heads A, and the shaft- B passes through such' heads, as well as through the pistonheads, and has its bearings in boxes on the stationary supporting-frame A as shown.

b are piston-valves adapted to slide in radial slots in the piston; O, a reversible valve arranged in the valve-casing O 00 cf, steamports; E, a fixed abutment between the ports, and F an eccentric for assisting in controlling the. action of the piston valves, as will be hereinafter described.

The piston-heads B are bolted to the efids of the" piston by bolts b, and each head is provided with radial slots b, which correspond to the radial slots in the piston itself, and is further provided with radial metal ribs b", which enter the slots of both head and piston and operate to more firmly connect said parts and prevent undue strain on the securingbolts.

' The piston-valves b are adapted to fit within the slots of the piston and piston-head, and are made a little shorter than the length of the piston, in order to admit the metal ribs 1) into the slots, as above explained. Each pistonvalve is grooved on its inner and lateral edges, in order that steam may be admitted behind such edges to prevent the valves from sticking or binding, and each valve is also provided with a seriesof holes or perforations, 1), extending through it from its outer to its inner edge, alsofor the purpose of admitting steam, and to quickly exhaust the steam from behind the valves when the latter are moved inward. When the valves are projected from the piston the middle portions, b of their outer edges come in contact with the inner surface of the fixed ring A, leaving the remaining portions of the outer edges and the lateral and inner edges exposed to the pressure of the steam. By reason of this contact of the middle portion of the outer edges of the valves, said edges are made to present a less area to the action of steam than thatpresented by the inner edges, and, as a consequence, the pressure on the inner edges is greater. While it is desirable that the pressure should be greater on the inner edge, such pressure should only slightly preponderate, and therefore to more nearly equalize'it the bearin g-surfaces b are formed on curves shorter than the curve of the inner surface of the fixed ring A, with which they come in contact, as shown in Fig. 7, whereby to reduce the area of the bearing-points and enable the steam to exert pressure on a larger surface.

- The ends f of the eccentric F areformed to fitinto lateral dovetailed recesses on the fixed ring, as shown, to enable the eccentric to be easily applied and removed, and to be held securely when in place. Midway of the eccentric the abutment E is located. It consists of a lower part, c, and an upper part, c. The lower part rests on the eccentric, and the upper part fits into a recess in the fixed ring A. A steel or rubber spring, a, is interposed between the two parts, and an adjusting-screw, 6 works into or against the upper part. The spring and screw operate to keep the eccentric in close contact with the rotating piston and to compensate for wear. The abutment extends out beyond the sides of the fixed ring and into annular recesses 11 in the pistonheads.

On opposite sides of the abutment, and behind the eccentric, the steam-ports a a are located. Either port may be an induction-port or an eduction-port, according to the direction in which the piston is to be rotated; but for convenience of description herein the port a will be designated as the induction-port.

The arrangement of the valves in the piston is such that in whatever position the piston is stopped some one or more of them will be, by gravity, projected against the inner surface of the fixed ring A, and in position to be operated upon by steam admitted into the chamber. Steam, entering through the inductionport a, passes on both sides of the fixed ring A, and, exerting its pressure against the projected valve, causes the piston to move around in the direction indicated by the arrow, Fig. 4. As each retracted valve passes the abutment the steam rushes in behind its lateral and rear grooved edges and through its perforations and forces the bearing-surface b of the valve against the eccentric, as before explained. The valve is held in contact with the eccentric, and afterward in contact with the inner surface of the fixed ring, till it reaches the eccentric again, when it is once more retracted within the piston. A relief-port, p, permits a partial escape of steam from immediately behind the valve before the latter reaches the eccentric and commences to retract. As it retracts the steam behind its rear edge is exhausted out through the perforations, and escapes, together with the steam remaining behind it, out through the eductionport.

It will be observed that the piston-heads embrace the sides of the fixed ring A, and, in the rotation of the piston, travel in contact therewith. To preserve a tight joint between the parts an annular groove, a, is formed in the bearing-face of each of the piston-heads, as shown in Figs. 3 and 5, and in this groove is placed a packing, a, of any suitable material, and a packing-ring, a Screws a are employed for properly adjusting the packing-ring. To enable the screws to be operated without removing the heads A of the stationary casin g, the latter are each provided with a tapped opening, b in the path of the set-screws, through which a key or other suitable instrument may be inserted, when necessary.

Should the joints between the piston-heads and the fixed ring leak, so as to permit an unequal quantity of steam to enter the stationary heads A, the unequal pressure of such escape steam would cause one piston-head to bear with greater friction upon the fixed ring than the other piston-head, and thus make the wear on the ring uneven. To guard against such result, perforations p'are made entirely through the piston and through both piston-heads, so as to put both fixed heads A into communication, and thus equalize the pressure on both heads.

The piston-heads are provided with holes or perforations a extending to the packing-ring a so as to enable the escape-steam in the heads A to operate to press the packing tightly against the bearing, and also to permit any condensed steam that may bein the heads A and the lubricant employed mixed therewith to enter said holes and keep the packing moist. Each of the heads A is provided with external screw-threads on its annular flange A and is adapted to engage with a correspondingly screw-threaded portion of the stationary casing A. The joint formed by this screw-connection is perfectly tight, and the necessity of grinding the parts to a joint or using a packing is dispensed with. Turning lugs or projections are cast or otherwise formed on the outer faces of the heads for the application of a turning-bar or lever to screw the heads on and off.

The valve 0, by which the introduction and exhaust of steam to and from the engine are controlled, is arranged so that it can be adjusted to introduce the steam either at the port a or at the port a, and exhaust it at the opposite port.

The induction-port c of the valve-casing is preferably arranged at the top, as shown, while the eduction-port c is in a removable plug, 0 screwed into the side of the casing, as shown. By unscrewing the screw-plug the valve can be easily removed and replaced without trouble or further derangement of the parts.

The bearing-surfaces b of the piston-valves may be case-hardened, or the whole valve be made of steel, so as to resist wear. The joint between the eccentric and piston is kept tight ordinarily by the spring interposed between the parts of the abutment; but when further adjustment is rendered necessary to compensate for wear the adjusting-screw is resorted to.

I claim as my invention- 1. In a rotary engine, the combination of a steam-chamber, havinginduction and eduction ports, with a rotating piston having radiallysliding valves, to which steam pressure is applied on both their inner and outer edges, with a superabundance of pressure on their inner edges, whereby to hold the valves against the wall of the steam-chamber, substantially as described.

2. In a rotary engine, the combination, substantially as described, of a stationary casing having an internal annular projection or fixed ring, a rotating piston provided with heads which embrace said fixed ring, sliding valves which work in radial slots in the piston and piston-heads and. are forced outward by steampressure, a fixed abutment, induction and eduction ports, and an eccentric for retracting the valves.

3. The combination, substantially as described, of the fixed ring of the casing, the rotating piston and its heads, and the sliding perforated valves, substantially as described.

4. The combination, with the fixed ring of the casing, the eccentric, and the rotating piston, of the sliding valves having their bearingsurface which works in contact with the ringformed on a shorter curve than the curve of the ring, to more vnearly equalize the steampressure on both outer and inner edges of the valves, substantially as described.

5. The sliding valves having grooves in their lateral and rear edges for the purpose of preserving steam-pressure on all edges of the valves and preventing binding, substantially as described.

6. The combination of the stationary casing having the internal annular projection or fixed ring, the rotating piston and its valves extendin g laterally on each side of the fixed ring, with the eccentric, the abutment, and the induction and eduction ports arranged to supply and exhaust steam on both sides of the fixed ring, substantially as described.

7. The combination, with the fixed ring of the casing and the rotating piston and valves, of the removable and adjustable eccentric, substantially as described.

8. The combination of the fixed ring, the twopart abutment with the spring between, and the adj usting-screw, substantially as described, for the purpose specified.

9. The piston heads provided with radial grooves and with metal ribs which enter said grooves and also the grooves of the rotating piston, and serve to hold the piston audits heads together and prevent undue strain on the securing-bolts, substantially as described.

10. The rotating piston-head having holes or perforations extending to the packing ring, whereby any escapesteam which may enter the head of the stationary casing will operate to press the packing tightly against the hearing, and whereby, also, any condensed steam in said head mixed with the lubricant employed will be permitted to enter the holes and keep the packing moist at all times, substantially as described.

11. The combination, with the stationary ring having the internal annular projection and the screw-threaded portions, of the screwthreaded casing-heads adapted to screw into the casin g and form a tight joint therewith without the necessity of grinding the parts to a joint or using packing, substantially as described.

GEORGE T. .ELLIS. Witnesses:

MELVILLE CHURCH, J AS. H. LANGE. 

